全文获取类型
收费全文 | 633289篇 |
免费 | 38406篇 |
国内免费 | 885篇 |
专业分类
耳鼻咽喉 | 8764篇 |
儿科学 | 20332篇 |
妇产科学 | 16038篇 |
基础医学 | 101070篇 |
口腔科学 | 18833篇 |
临床医学 | 51803篇 |
内科学 | 123019篇 |
皮肤病学 | 15917篇 |
神经病学 | 45773篇 |
特种医学 | 21023篇 |
外国民族医学 | 64篇 |
外科学 | 91580篇 |
综合类 | 9098篇 |
一般理论 | 155篇 |
预防医学 | 50718篇 |
眼科学 | 14735篇 |
药学 | 48852篇 |
中国医学 | 1629篇 |
肿瘤学 | 33177篇 |
出版年
2021年 | 5544篇 |
2019年 | 6189篇 |
2018年 | 9607篇 |
2017年 | 6407篇 |
2016年 | 6650篇 |
2015年 | 7380篇 |
2014年 | 9344篇 |
2013年 | 14521篇 |
2012年 | 21678篇 |
2011年 | 23625篇 |
2010年 | 12981篇 |
2009年 | 11015篇 |
2008年 | 21052篇 |
2007年 | 22684篇 |
2006年 | 22190篇 |
2005年 | 21584篇 |
2004年 | 20433篇 |
2003年 | 19317篇 |
2002年 | 18857篇 |
2001年 | 27315篇 |
2000年 | 28795篇 |
1999年 | 23352篇 |
1998年 | 5876篇 |
1997年 | 5000篇 |
1996年 | 5312篇 |
1995年 | 4849篇 |
1992年 | 16807篇 |
1991年 | 17234篇 |
1990年 | 17252篇 |
1989年 | 16480篇 |
1988年 | 15143篇 |
1987年 | 14995篇 |
1986年 | 14140篇 |
1985年 | 13448篇 |
1984年 | 9963篇 |
1983年 | 8517篇 |
1982年 | 4692篇 |
1979年 | 9727篇 |
1978年 | 7039篇 |
1977年 | 5954篇 |
1976年 | 5794篇 |
1975年 | 6636篇 |
1974年 | 7912篇 |
1973年 | 7444篇 |
1972年 | 7230篇 |
1971年 | 6971篇 |
1970年 | 6447篇 |
1969年 | 6161篇 |
1968年 | 5803篇 |
1967年 | 5231篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
In a randomized, double-masked study, 41 patients with primary open-angle glaucoma or ocular hypertension were treated with betaxolol 0.5% or timolol 0.5% drops for 26 weeks. The average decrease in intraocular pressure (IOP) over the total study period was significant with both betaxolol (-6.3 mmHg) and timolol (-7.2 mmHg) in patients receiving no adjunctive therapy. There was no difference between betaxolol and timolol with respect to changes from baseline IOP. Significantly decreased mean brachial arterial pressure (MAP) was seen only with timolol, although the difference between the two groups was not significant. Pulse, pupil size, and basal tear secretion were unchanged in both groups. Burning upon instillation of the drops was more frequent with betaxolol. 相似文献
993.
994.
995.
C DeCarli J Maisog D G Murphy D Teichberg S I Rapoport B Horwitz 《Journal of computer assisted tomography》1992,16(2):274-284
We describe a simple, rapid, and semiautomated method of MR analysis based on mathematical modeling of MR pixel intensity histograms. The method is shown to be accurate and reliable for regional analysis of brain, central, and subarachnoid CSF volumes. Application of the method to five young and six older subjects revealed significant age-related changes in regional brain volumes whereas no difference was found for traced central CSF volumes or subarachnoid CSF volumes. We conclude that this is a simple method that can be applied to further studies of quantification of brain structure in healthy aging and brain disease. 相似文献
996.
997.
The presence of vascular permeability factors in the extracellular products (ECP) of 10 strains of Renibacterium salmoninarum with different geographical origin and serological characteristics are reported. All the ECP produced haemorrhagic and/or oedematous zones at the injection site with a diameter ranging from 10-30 mm. However, the ECP samples did not display toxic effect in fish at the same dose as inoculated in rabbit (180-400 micrograms protein/0.1 ml). No differences were observed in the production of this dermatotoxic factor between the two antigenic groups found in this microorganism. Whereas heating (80 and 100 degrees C/15 min) the ECP samples resulted in a complete loss of their proteolytic activity, only a decrease (but not total inactivation) of the dermatotoxic effects was detected. Therefore, although proteases could be implicated in the permeability factor, they are not totally responsible for this activity. 相似文献
998.
E D Barnett J O Klein S I Pelton L M Luginbuhl 《The Pediatric infectious disease journal》1992,11(5):360-364
Acute otitis media (AOM) is thought to occur frequently in children infected with human immunodeficiency virus (HIV). We compared experience with AOM of 28 HIV-infected children with that of 33 children who seroreverted to HIV antibody negative status by age 18 months. The mean number of episodes/year of AOM for children who seroreverted decreased from 1.33 in the first year of life to 0.13 in the third year, whereas the mean number of episodes/year in HIV-infected children increased from 1.89 to 2.40. By age 3 years, all HIV-infected children had experienced 1 or more episodes of AOM, and 80% had experienced 6 or more, whereas 75% of children who seroreverted had experienced 1 or more episodes, and none had had 6 or more. HIV-infected children with normal T4 lymphocyte counts had a mean of 1.18 episodes of AOM in the first year of life compared with 2.35 episodes in HIV-infected children with decreased counts (P = 0.023). HIV-infected children with low counts had a nearly 3-fold increased risk of recurrent AOM (47% vs. 18%). 相似文献
999.
1000.